the sqa charter find defects so they can be removed anticipate defects so they can be prevented. ...

THE SQA CHARTER

Find defects so they can be REMOVED

Anticipate defects so they can be

PREVENTED.

Software Quality Assurance

CONCEPTS: The Two V's

Validation: "Are we building the right product?"[End-User]Verification: "Are we building the

product right?"

NOTE:A program totally lacking documentation may pass the test of VALIDATION, but may fail VERIFICATION if the organization

requires comments in the code.


PREMISE

Definition: Correctly following a correct process yieldsa correct product.

Thus, SQA has three concerns:(1) End-product(2) The process(3) Adherence to the process


SQA is concerned with PROCESS IMPROVEMENT

(1)An excellent process prevents certain defects

(2) A good process detects certain defects and ensures that they are REMOVED

(3) Defects can be traced back to steps in the process where they are introduced, or where they escaped detection.

(4) An excellent process traces defects back to the root cause, then eliminates the root cause.


A DILEMA: CONSISTENCYExample: Suppose you took an English paper to

three different

teachers and go grades of C, A, and B. Each

grade reflects

that teacher's judgment of the QUALITY of the

paper. But

lack of consistency makes it hard for you to

know the true

quality of the paper.

Consistency Requirement: The judgment of

quality must be independent of the person

performing the assessment. SQA must be more

that a set of opinions.


FOUNDATIONS OF SQA:

MENTALITY: SQA is obsessive about finding defects.STANDARDS: Set of products generated by a software development, and the rules for creating the product.• content -- what must be included in the product• style -- the appearance/format of product (e.g.,double-spaced, font size, layout)• semantics -- whether the information is meaningful and correct.


FOUNDATIONS OF SQA [continued]

Standards must be well defined, and assistance must be provided to ensure conformance to style and content:

std_ file => definition of the productfrm_ file => blank form for specifying an actual product.



CHECKLISTS: List of the types of defects (errors) that may occurfor a given type of product.• Each type of product has its own checklist• Checklist is NEGATIVE, pointing out the type of DEFECT• Checklist is based on ACTUAL ERRORS

-items will be added as needed-some items will become obsolete when

the process begins to prevent a particular type of

defect



DEFECT METRICS: Defects of each type are tallied (counted) and reported. It is possible to identify the MOST COMMON defect, and to show TRENDS (over time, some defects should drop off the "best seller" list).



CAUSAL ANALYSIS: SQA should understand when and how a particular defect was introduced.• Problem tracking database • Root cause analysis• Recommendation for process improvement to prevent or detect defect• Defect "age analysis" -- how long defect existed before beingdetected.


THE IMPACTS OF SQA ON AN ORGANIZATION:(1) ATTITUDES:• Usually SQA seen in negative light, since their job is tobring BAD NEWS (here's what's wrong)• Positive perspective: SQA "has the back" of the softwaredevelopers, even the organization.• SQA should be integrated into the software process, ratherthan lying in ambush after the fact.

(2) SQA may cause REWORK to be done• Resistance by developers, management, because of schedule• Slips and cost overruns.• Organization must understand the COST OF QUALITY: Lack of quality results in loss of customers (sales revenue).


THE SQA QUALITY AUDIT

Function: Perform an assessment of the quality of a product.

Inputs: Products (e.g., files containing one or more productsof the given type)Product Standards (from SQA)Checklist (from SQA)

Outputs: Tallied checklistsRed-lined (edited, handwritten) hardcopiesAudit summary reportRevisions to the checklist


THE SQA QUALITY AUDIT [continued]

Follow-Up:SQA disseminates findings to developersDevelopers fix errorsFindings as inputs to Defect Causal AnalysisFindings combined into organization statistics


THE SQA CHARTER

Find defects so they can be REMOVED

Anticipate defects so they can be

PREVENTED.


THE END OF THIS MODULE

This is THE END of the


Module !!!


the sqa charter find defects so they can be removed anticipate defects so they can be prevented. ...

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